Garden path sentence

A garden path sentence is a grammatically correct sentence that starts in such a way that a reader's most likely interpretation will be incorrect; the reader is lured into a parse that turns out to be a dead end. Garden path sentences are used in psycholinguistics to illustrate the fact that when human beings read, they process language one word at a time. "Garden path" refers to the saying "to be led down the garden path", meaning to be deceived, tricked, or seduced.

As a person reads a garden path sentence, the reader builds up a structure of meaning one word at a time. At some point, it becomes clear to the reader that the next word or phrase cannot be incorporated into the structure built up thus far; it is inconsistent with the path down which they have been led. Garden path sentences are less common in spoken communication because the prosodic qualities of speech (such as the stress and the tone of voice) often serve to resolve ambiguities in the written text. This phenomenon is important in theoretical linguistics, and is discussed at length by literary theoristStanley Fish.

Simple ambiguity does not produce a garden path sentence; rather, there must be an overwhelmingly more common meaning associated with the early words in a sentence than is involved in a correct understanding. Whether a sentence is misleading can thus be a matter of degree, and will depend on the idiolect of the reader or listener, who may be more or less familiar with particular word meanings.

Garden path sentences are related to paraprosdokian, where the latter part of an utterance or discourse is unexpected and causes the reader or listener to have to think about what they previously heard in a new light. A common example is a pun employing antanaclasis: a word or phrase appears; it then reappears and is (at first) understood as a grammatical or rhetorical parallel to what had gone before;[1] however, the rest of the sentence makes it clear that the second use must be different from the first.

A standard reader begins to put the first clause together conveying the vague sense that "time passes rather quickly". The concrete nature of fruit actually strengthens the imagery, producing a stronger notion of an actual speeding arrow. The obviousness of fruit flying like a member of its class and the poor aerodynamic properties of bananas[citation needed], however, force a reappraisal: "fruitflies" goes from being its clause's subject and verb to an adjective and its referent, "fruit flies"; "like" similarly goes from its meaning as a marker of similes to its meaning as a verb. This new understanding can't apply to the first clause ("time flies" not being a kind of fly), and the two phrases are recognized as unrelated.

(For the classically minded, the first half also functions as a garden path sentence. "Time flies" is a traditional English translation of the Latin proverb tempus fugit distilled from Virgil's quote fugit irreparābile tempus: "it flees, irretrievable time". This confounding of the senses of "flee" and "fly" appears as early as Old English[2] but Virgil's image is one of escape on foot. The use of an arrow in the simile, however, jerks such a reader back to the airborne sense of flight.)

Most readers initially parse this as a basic noun phrase followed by the ordinary activeintransitiveverb "raced" and the prepositional phrase "past the barn", but stumble when reaching the word "fell". At this point, the reader is forced to backtrack and look for other possible structures. It may take some rereading to realize that "raced past the barn" is in fact a reduced relative clause with a passiveparticiple, implying that "fell" is the main verb. The correct reading is then "The horse—(that was) raced past the barn—fell."

This sentence can be parsed in other ways as well: A British reader accustomed to "fell" being a noun (meaning "mountain") may reach the end and still treat "raced" as the verb and "barn fell" as "the fell by or at the barn". Fell is also an adjective that means "dreadful" or "wicked". Chiefly archaically and poetically, adjectives may follow their noun leading to the somewhat nonsensical "The horse raced past the dreadful barn."

The example hinges on the ambiguity of the lexical category of the word "raced": It can be either a past-tense verb or a passive participle. Compare to an unambiguous sentence with the same syntactic structure: The car driven past the barn crashed. Unlike "raced," the verb "driven" is unambiguously passive, thus eliminating the garden path reading.

Garden path sentences mostly appear in analytic languages, where word order is heavily relied upon to establish the grammatical case and function in a sentence. More synthetic languages, which establish grammatical function in a sentence through inflection and other types of relational synthesis, mostly avoid this type of ambiguity because the relationship of a word to the surrounding words is marked by the way the word is modified.

When reading a sentence, readers will analyze the words and phrases they see and make inferences about the sentence’s grammatical structure and meaning in a process called parsing. Generally, readers will parse the sentence chunks at a time and will try to interpret the meaning of the sentence at each interval. As readers are given more information they make an assumption of the contents and meaning of the whole sentence. With each new portion of the sentence encountered, they will try to make that part make sense with the sentence structures that they have already interpreted and their assumption about the rest of the sentence. The garden path sentence effect occurs when the sentence has a phrase or word with an ambiguous meaning that the reader interprets in a certain way, and when they read the whole sentence there is a difference in what has been read and what was expected. The reader must then read and evaluate the sentence again to understand its meaning. The sentence may be parsed and interpreted in different ways due to the influence of pragmatics, semantics, or other factors describing the extralinguistic context.[3]

Various strategies can be used when parsing a sentence, and there is much debate over which parsing strategy humans use. Differences in parsing strategies can be seen from the effects of a reader attempting to parse a part of a sentence that is ambiguous in its syntax or meaning. For this reason, garden path sentences are often studied as a way to test which strategy humans use.[4] Two debated parsing strategies that humans are thought to use are serial and parallel parsing.

Serial parsing means that the reader makes one interpretation of the ambiguity, and continues to parse the sentence in the context of the interpretation. The reader will continue to use their initial interpretation as reference for future parsing until disambiguating information is given.[5]

Parallel parsing means that the reader generates multiple interpretations of the sentence and stores them until disambiguating information is given, at which point only the correct interpretation is maintained.[5]

When ambiguous nouns appear, they can function as both the object of the first item or the subject of the second item. In that case the former use is preferred. It is also found that the reanalysis of a garden path sentence gets more and more difficult with the length of the ambiguous phrase.[6]

A research paper published by Meseguer, Carreiras and Clifton (2002) stated that intensive eye movements are observed when people are recovering from a mild garden path sentence. They proposed that people use two strategies, both of which are consistent with the selective reanalysis process described by Frazier and Rayner in 1982. According to them, the readers predominantly use two alternative strategies to recover from mild garden path sentences.

The more common one includes the regression of eyes from the first disambiguation directly to the main verb of the sentence. Then the readers reread the remaining of the sentence, fixating their eyes to the next region and the adverb (the beginning of the ambiguous part of the sentence).

The second and least used strategy includes the regression from the first disambiguation directly to the adverb.[7]

Partial reanalysis occurs when analysis is not complete. Frequently, when people can make even a little bit of sense of the later sentence, they stop analyzing further so the former part of the sentence still remains in memory and does not get discarded from it.

Therefore, the original misinterpretation of the sentence remains even after the reanalysis is done; hence participant’s final interpretations are often incorrect.[8]

One way to determine the brain processes involved is the use of brain electrophysiology. Brain electrophysiology is used to study the impact of disfluencies[clarification needed] in sentence processing by the brain, which specifically use event-related potentials (ERPs). ERPs are voltages generated by the brain that can be measured through a device placed on the scalp. It is also observed that specific components of the ERPs can be associated with the activation of different and specific linguistic processes of the brain.[9] Within ERPs, P600 is the most important component. Its activation occurs when the parser comes across a syntactic violation such as The broker persuaded to sell the stock[10] or when parses synthesizes an unsatisfactory disambiguation on an ambiguous string of words such as The Doctor Charged the patient was lying.[11] Hence the activation of P600 marks the parser's attempt to revise the sentence's structural mis-match or ambiguity. However it is also observed that the activation of P600 may be low or completely absent if the parser is asked to pay attention only to the semantic aspects of a sentence either through an explicit instruction [12] or through the use of specific words as a way to force a semantic analysis of the sentence.[13] The result of yet another study conducted by Osterhout in 1997 reveal that the activation of P600 varies with the parser's own attentions to the syntactic violations of the sentence.[14]

Disfluent sentences have a direct effect on the way a sentence structure is built in the parser's mind. Depending on its location within a sentence, a disfluency either aids in the computation of a sentence or forces the parser to linger on the sentence for a longer period of time. It is observed that the more an individual lingers on an incorrect parse, the more it is likely that the sentence will end up being interpreted incorrectly.[15] It also appears[clarification needed] that the presence of a disfluency in a sentence—caused by filled and long silent parses—does not elicit the P600. Instead, it elicits another ERP component, N400, which gets activated when people try to integrate a new word into the preceding sentence's context.[15]